The Food Standards Agency (FSA) said the website – which also rates shops, businesses and restaurants – only has ratings for 29 of Flintshire’s 89 schools because the scheme is new and only a third have so far been inspected.

A spokesman added: “Each business is given a hygiene rating when it is inspected by a food safety officer from the local authority.

“The rating shows how closely the business is meeting the requirements of food hygiene law.

“The food safety officer checks how hygienically the food is prepared, the condition of the buildings and how the business manages and records what it does to make sure food is safe.”

He added: “The food safety officer will explain to the person who owns or manages the business what improvements are needed and how they can achieve the top rating. The local authority will check that these improvements are made.”